[1] It is an arbovirus, being primarily transmitted to humans from the bite of infected mosquitoes of the genus Culex.

BAV is a small (72–75 nm in size), non-enveloped, double-stranded RNA virus surrounded by an icosahedral protein coat.

The genome of BAV is about 19,500 base pairs in length, linear and segmented into 12 parts, encoding for genes VP1-12.

[10] Banna virus was first isolated from the cerebrospinal fluid of encephalitis patients in Xishuangbanna, Yunnan province, People's Republic of China in 1987.

Subsequent identification came in the Xinjiang province and the virus has since been found elsewhere in China, Indonesia, and Vietnam in mosquito populations.